| 摘要 |
<p>PURPOSE:To enable electrolytic corrosion not to be generated to a thermal head, by supplying supply voltage to the thermal head only when a printing signal is outputted. CONSTITUTION:A printing signal from a printer circuit 5 is given a thermal head 3 via a signal wire 4. When this printing signal is outputted, the printer circuit 5 gives a control signal prior to the printing signal a photocouplor 7. A light emitting diode 7a of the photocouplor 7 emits light and makes a light receiving transistor 7b to be operated. A power source 8 is brought into an operation state thereby, and electric power is supplied to the thermal head 3. When output of the printing signal is ended, the printer circuit 5 stops output of the control signal. Therefore, electric power supply to the thermal head 3 by the power source 8 is stopped. Then, when printing is performed again, the control signal is outputted from the printer circuit 5, and electric power is supplied to the thermal head 3 from the power source 8.</p> |
